X-ray devices, such as X-ray detectors or X-ray converters may transform X-ray radiation into optical photons. These devices may provide an image. An X-ray detector or an X-ray converter may comprise one or a plurality of sensor elements, which may provide one or a plurality of electrical signals. These sensor elements may comprise an array or a matrix of single pixels. Each pixel may contribute to an image taken by the X-ray detector. The sensor elements may comprise a transfer function, respectively.
U.S. Pat. No. 4,777,428 describes a device for compensation of transfer functions. A signal from a unit to be compensated is connected to a differential amplifier with a feed-back network having a transfer function that is substantially the same as the transfer function to be compensated. A compensation device has a transfer function that approximately is inverse to the transfer function of the sensor. A signal that the sensor senses and that is distorted by a non linear transfer function is restored.
The image quality of an X-ray device may be dependent on the voltages or charges provided by each pixel. Voltages or charges provided by the pixels may be influenced by many factors, such as coupled voltage from a bus system and/or leakage currents. Moreover, structural noises may be present.